.select_all select{
    width: 42%;
    margin-left: 5%;
    height: 30px;
    margin-top: 10px;
    border-radius:5px; 
}
.select_all input{
    width: 42%;
    margin-left: 5%;
    height: 30px;
    margin-top: 10px;
    border-radius:5px;
    border: 1px solid #999;
    text-indent: 10px; 
}
.student_list{
    width: 100%;
    font-size: 14px;
    text-align: center;
    border-collapse: collapse;
    margin-top: 20px;
    background: #fff;
}
.student_list tr{
    height: 40px;
    border-bottom: 1px solid #dddddd; 
}